Ago and before

Ago describes how far back in the past something happened.

Before describes when an action or event took place in relation to another action or event.

Ago

• She changed her job six weeks ago.
• The situation was a lot worse a year ago.
• I started my current job twenty years ago.

Before

• I always drink a cup of coffee before I start work.
• Can you switch the lights off before you leave the office.
• Can you speak to me before you speak to her.